The Urban Dictionary T-Shirt

The perpetual trademark of our species. The random and unpredictable state of mind that causes and governs wars, unwanted pregnancies, political actions, divorces, ripoffs, reality TV shows, copycat crimes, cults, self-injury, and lawsuits.
Since the stupid in our midst are breeding uncontrollably while the intelligent minority are dying out, one can easily predict that our stupidity will far outpace our technological progress within a few decades, and propel us back to the Stone Age or extinction with in a few centuries.

You can never go broke by underestimating the stupidity of the human race.